kernel/time/timekeeping_internal.h

   1 #ifndef _TIMEKEEPING_INTERNAL_H
   2 #define _TIMEKEEPING_INTERNAL_H
   3 /*
   4  * timekeeping debug functions
   5  */
   6 #include <linux/clocksource.h>
   7 #include <linux/time.h>
   8
   9 #ifdef CONFIG_DEBUG_FS
  10 extern void tk_debug_account_sleep_time(struct timespec64 *t);
  11 #else
  12 #define tk_debug_account_sleep_time(x)
  13 #endif
  14
  15 #ifdef CONFIG_CLOCKSOURCE_VALIDATE_LAST_CYCLE
  16 static inline u64 clocksource_delta(u64 now, u64 last, u64 mask)
  17 {
  18         u64 ret = (now - last) & mask;
  19
  20         /*
  21          * Prevent time going backwards by checking the MSB of mask in
  22          * the result. If set, return 0.
  23          */
  24         return ret & ~(mask >> 1) ? 0 : ret;
  25 }
  26 #else
  27 static inline u64 clocksource_delta(u64 now, u64 last, u64 mask)
  28 {
  29         return (now - last) & mask;
  30 }
  31 #endif
  32
  33 extern time64_t __ktime_get_real_seconds(void);
  34
  35 #endif /* _TIMEKEEPING_INTERNAL_H */